ipod won't play previews.

My ipod won't play the previews in the itunes store. Well, it just loads them but it loads them for a long time and they just wont play. It also takes a while to download a song and an app.
It just recently started doing this.

I have about 20GB of free storage left on my ipod.
I have tried restoring and resetting it, but it just wont solve the problem.
Is anyone else having the same problem?
or does anyone know how to fix it?